Alnus incana 'Angustissima'

Trees

A medium-growing deciduous tree to 20m. The green leaves are reduced almost to a skeleton around the veins, making a delicate feather and casting much less shade. There is a brief period of light yellow leaves before they fall in autumn. In late winter the purple-brown male catkins open cream to 8cm long and female woody cones are held in clusters right through the winter.

Position

Full sun

Soil Types

Clay, Loam

Max Height

Higher than 12 metres

Max Spread

wider than 8 metres

Size

Time to Maturity
20–50 years
Max Spread
wider than 8 metres
Max Height
Higher than 12 metres

Growing Conditions

Clay Loam
Moisture
Poorly–drained
pH
Acid or Alkaline or Neutral

Position

Full sun
Aspect
East–facing or North–facing or South–facing or West–facing
Exposure
Exposed or Sheltered
Hardiness
H7

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Betulaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Spreading branched, Columnar upright
Genus
Alnus are vigorous deciduous trees and large shrubs with rounded leaves and often conspicuous catkins in winter
Name Status
Accepted

How to Grow

Cultivation

It is a nitrogen-fixer so can grow on poor soil. Suited to river banks on permanently damp soil in good light. For more information see tree cultivation.

Propagation

Propagate from hardwood cuttings in autumn

Suggested planting locations and garden types

  • Architectural
  • Banks and slopes

Pruning

Pruning group 1

Pests

May be susceptible to alder leaf beetle, alder sucker and leaf-mining sawflies

Diseases

May be susceptible to phytophthora root rot and honey fungus